BORE-HOLE INVESTIGATIONS 



nil 



B e 



STRUCTURAL CORRELATION ON SHALE 



Fig. 695. 

 (Courtesy of Lane-Wells Company.) 



RAOIOICTIVITT INCREASES 



GAMMA NEUTRON 6AMMA NEUTRON GAMMA NEUTRON GAMMA NBJTRON GAMMA NEUTROH GAMMA NEUTRON 



A - HEEBNER 

 e - TORONTO 

 C - DOUGLAS 

 D - LANSING 

 C — ARBUCXLE 

 f —VIOLA 



Fig. 696. — Radioactivity increases. 



